Under spec'd WAAS Appliance

[garry cordess]

Hello,

This hasn't happened so its purely theoretical.

What would be the outcome if a WAAS appliance was under spec'd? If the traffic thoughput was greater than the appliance could handle. Is it just a case of it going into pass-thru mode?

Any info would be greatly appreciated.

Regards,

Garry.

[Michael Korenbaum · Accepted solution]

Garry,

In an overload condition the WAE will not optimized new TCP connections; they will be classified as pass-through until this condition is cleared (e.g. existing optimized TCP sessions are completed; FIN/FIN-ACK, or RST by client/ server).

Here is a good link that explains overload conditions in WAAS:

http://docwiki.cisco.com/wiki/Cisco_WAAS_Troubleshooting_Guide_for_Release_4.1.3_and_Later_--_Troubleshooting_Overload_Conditions

If you have further sizing questions feel free to open a case with the PDI Help Desk.

http://www.cisco.com/web/partners/tools/pdi.html

Regards,

Mike Korenbaum

Cisco Data Center PDI Help Desk

http://www.cisco.com/go/pdihelpdesk

[garry cordess]

Hi Michael,

Ok thats great, many thanks for the response.

Regards,

Garry.

[garry cordess]

Hi Michael,

Would the condition be similar if for example a WAAS appliance suited to a 20M line was connected to a 100M line?

Regards,

Garry.

[Michael Korenbaum]

Gary,

Overload conditions occur when connection limits are reached on WAAS, and are not based on WAN bandwidth.

In the sizing guides the WAN bandwidth listed for each appliance has this note:

"WAN bandwidth is not limited in software or by any other system limit; rather it is provided as guidance for deployment sizing purposes and is based on possible WAN usage using multiple TCP connections. WAN link utilization will be determined by compression ratio and client/server behavior."

Regards,

Mike

[garry cordess]

Hi Mike,

Ok thanks again.

Regards,

Garry.